#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
#include"string.h"
#include<iostream>
using namespace std;
int main()
{
	kl::string s1="hello world";
	s1.push_back('x');
	cout << s1.c_str() << endl;
	s1.push_back("adoiioaoi");
	cout << s1.c_str() << endl;
	s1.insert(0, '=');
	cout << s1.c_str() << endl;
	s1[1];
	const kl::string s2="hello world";
	cout << s2.c_str() <<endl;
	s2[1];
	return 0;
}